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Mail Archives: pgcc/1999/06/17/11:14:39

Sender: jon AT blackhole DOT isdn DOT uiuc DOT edu
Message-ID: <3768B5EE.A92B518F@uiuc.edu>
Date: Thu, 17 Jun 1999 03:46:38 -0500
From: JonMcK <jcmcknny AT uiuc DOT edu>
X-Mailer: Mozilla 4.6 [en] (X11; I; Linux 2.2.5-22 i686)
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MIME-Version: 1.0
To: pgcc AT delorie DOT com
Subject: Re: pgcc does better, reboot, then does terrible!
References: <3767970F DOT 307F679C AT uiuc DOT edu>
Reply-To: pgcc AT delorie DOT com

Here's some additional info on the binaries(my physics code) where the first
compiled with pgcc is fast, while after I rebooted linux the pgcc compiled
is slow.

In the binary itself(I have -pg) I noticed the following human readable
differences(this is a chunk of contiguous binary data):

SLOW:

LPBIG_OFFBIG_LINTFLAGS:1115,;^@../include/getopt.h^@../posix/getopt.h^@ptrdiff_t:t(52,1)=(0,1)^@__gmon_start__:F(0,19)^@called:V(0,1)^@^@GCC:
(GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU)
egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66 19990314
(egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66 19990314 (egcs-1.1.2
release)^@^@GCC: (GNU) pgcc-2.91.66 19990314 (egcs-1.1.2 release)^@^@GCC:
(GNU) pgcc-2.91.66 19990314 (egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66
19990314 (egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66 19990314
(egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66 19990314 (egcs-1.1.2
release)^@^@GCC: (GNU) pgcc-2.91.66 19990314 (egcs-1.1.2 release)^@^@GCC:
(GNU) pgcc-2.91.66 19990314 (egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66
19990314 (egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66 19990314
(egcs-1.1.2 release)^@^@GCC: (GNU) pgcc-2.91.66 19990314 (egcs-1.1.2
release)^@^@GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^^


FAST:


LPBIG_OFFBIG_LINTFLAGS:1115,;^@../include/getopt.h^@../posix/getopt.h^@ptrdiff_t:t(52,1)=(0,1)^@__gmon_start__:F(0,19)^@called:V(0,1)^@^@GCC:
(GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU)
egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)
^@^@GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC:
(GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU)
egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)^@^@GCC: (GNU) egcs-2.91.66
19990314/Linux (egcs-1.1.2
release)^^@^@^@^@^@^@^@^A^@^@^@01.01^@^@^^@^@^@^@^@^@^@^A^@^@^@01.01


Yes, I have the order right.  If you'll notice the SLOW one mentions pgcc
sometimes while the FAST one doesn't.  BTW, the FAST one is a little larger
than the SLOW one.

I KNOW both were compiled with pgcc since I used -mcpu=pentiumpro
-march=pentiumpro for both the above.

What might be the source of the above difference?  It may tell me what's
different and so what I can fix.

Anybody except newbies like me read this list??

What does binutils install when you install from the source?  Library stuff
at all?  I think so.  But what?  And how do I revert to what redhat6.0 uses?
I tried installing the binutils rpm but no speed changes.

Thanks,
Jon

JonMcK wrote:
> 
> I'm confused as heck.  Here's some info:
> 
> [jon AT blackhole Exe]$ gcc -v
> Reading specs from
> /usr/local/lib/gcc-lib/i686-pc-linux-gnu/pgcc-2.91.66/specs
> gcc version pgcc-2.91.66 19990314 (egcs-1.1.2 release)
> 
> -------
> 
> Here's my confusion.  I'm programming some physics stuff.  I've been
> optimizing my code and thought I'd try out pgcc.  Compiled it myself with
> bootstrap and low and behold all the profile times decreased on my
> P2-333/Redhat6.0 system.  Happy days are here!
> 
> Here's my CFLAGS:
> CFLAGS = -Wall -mpentium -mcpu=pentiumpro -march=pentiumpro -O4 -pipe
> -malign-loops=2 -malign-jumps=2 -malign-functions=2 --fast-math -pg
> 
> -pg or not the problem below is the same.
> 
> I read about binutils2.9.1 being needed for mmx, etc. so I decided to
> compile->install that.  I wasn't sure what version I already had, turns out
> I think I had 2.9.1.  Oddly, my compiled binutils files are huge!  I didn't
> realize "larger" meant 10X larger!   Anyways, this isn't the problem.
> 
> [jon AT blackhole Exe]$ ls -al /usr/bin/gprofold
> -rwxr-xr-x   1 root     root        95668 Apr  5 20:08 /usr/bin/gprofold
> [jon AT blackhole Exe]$ ls -al /usr/local/bin/gprof
> -rwxr-xr-x   1 root     root      1045169 Jun 16 03:07 /usr/local/bin/gprof
> 
> ------------
> 
> I then decided to recompile my kernel(2.2.5-22).  That went fine, modules
> installed, etc.  I reboot and to my UTTER HORROR after checking some times
> on my code it's all ALOT slower, by about 30%. Essentially losing 2 days
> worth of optimizing!!
> 
> Ok, I thought.  Must be the kernel and/or modules.  So I revert back to my
> previous kernel/modules(I always have a backup).  TO MY HORROR it's still
> slow as heck!
> 
> I looked at all my options, trying to see if I just happened to change
> something, then I remember a directory where I compiled the old good
> version.  I run that binary, and it's FAST, just like it was before!  I then
> move that in a safe place and recompile with the EXACT same settings as that
> FAST one was compiled.  I run it, and it's SLOW!  I compare the binaries and
> they are DIFFERENT!
> 
> Sorry, I've just been scratching my head for the past 4 hours.  I'm a little
> erked.
> ----------
> 
> My questions:
> 
> 1) WHAT THE HECK did I do?  Could binutils do this?
> 
> 2) The binaries are just 50k each, but the FAST one is a bit larger.  WHY?
> What changed?  HELP!
> 
> The above is what I did over a period of 2 hours or so, it's all that
> happened!
> 
> Please help me!
> 
> Thanks,
> Jonathan McKinney

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